Life Sciences (XL) PYQs Feb 2022

Physiology Ecology and Evolution

The dry bulb temperature and relative humidity of air inside a storage chamber are 37 ⁰ C and 50%, respectively. The sat

Biologically, verbal and logical reasoning operates via grammar, vocabulary and inference determine correct usage. Thus Option NAT is appropriate since it meets linguistic and logical standards, reinforcing core concepts taught in general aptitude.

Ref: Agrawal, Quantitative Aptitude, Chapter 5, Logical Reasoning and Probability, covers ratios, percentages, probability and inference explaining problem-solving strategies for competitive assessments.

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Physiology Ecology and Evolution

In a dairy processing plant, milk enters a 30 m long and 2 cm diameter tube at 60 ⁰ C and leaves at 57 ⁰ C. The total he

Biologically, photosynthetic regulation operates via light harvesting and carbon fixation coordinate energy flow. Thus Option NAT is appropriate since it supports efficient energy conversion, reinforcing core concepts taught in plant biology.

Ref: Raven, Evert and Eichhorn, Biology of Plants, 8th Edition, Chapter 22, Plant Development and Hormonal Control, explains phytohormones and environmental responses regulating growth.

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Physiology Ecology and Evolution

In a canning industry, the total process time (F0) was calculated as 3 min. If each can contains 20 spores having decima

verbal and logical reasoning analysis shows grammar, vocabulary and inference determine correct usage. Consequently Option NAT emerges as the valid choice since it meets linguistic and logical standards, aligning with established principles in general aptitude literature.

Ref: Wren and Martin, High School English Grammar and Composition, Revised Edition, Chapter 12, Vocabulary and Usage, discusses synonyms, spelling rules and comprehension providing guidance for verbal aptitude.

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Physiology Ecology and Evolution

One hundred kg paddy is dried from 18% wet basis to 13% wet basis moisture content. The amount of water removed (in kg)

In general biology, core biological organization dictates that structure-function relationships govern cellular processes. Therefore Option NAT is correct as it integrates fundamental life science principles, supported by mechanistic studies and conserved across related systems.

Ref: Alberts et al., Essential Cell Biology, 5th Edition, Chapter 1, Introduction to Cells, covers cellular organization and molecular mechanisms offering integrated perspective.

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Physiology Ecology and Evolution

The average body length of Drosophila nasuta collected from Andaman and Nicobar Islands is 2 mm. From this population, a

Mechanistically, evolutionary adaptation involves selection and population dynamics shape traits. This validates Option NAT because it explains adaptive diversity, a pattern repeatedly demonstrated in ecology and evolution research. This mechanism is extensively documented and reinforced by experimental data across multiple model systems and textbook discussions.

Ref: Begon, Townsend and Harper, Ecology: From Individuals to Ecosystems, 4th Edition, Chapter 5, Population Ecology, discusses population dynamics, life histories and community interactions explaining ecological stability.

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Physiology Ecology and Evolution

A typical food chain involves producers, herbivores, primary carnivores and secondary carnivores. Based on Lindeman’s la

Biologically, molecular bonding operates via hybridization and orbital overlap dictate geometry and reactivity. Thus Option NAT is appropriate since it satisfies bonding and stability criteria, reinforcing core concepts taught in chemistry.

Ref: Clayden et al., Organic Chemistry, 2nd Edition, Chapter 5, Pericyclic Reactions, covers Diels-Alder cycloaddition and stereochemistry providing foundation for organic transformations.

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Physiology Ecology and Evolution

If the vital capacity (VC) of an individual is 4900 ml, the tidal volume (TV) is 500 ml, and the inspiratory reserve vol

This outcome reflects core biological organization, where structure-function relationships govern cellular processes. Option NAT captures this correctly because it integrates fundamental life science principles, consistent with textbook descriptions and experimental observations in general biology.

Ref: Campbell et al., Biology, 11th Edition, Chapter 2, Chemical Basis of Life, discusses fundamental biological principles and molecular organization providing broad foundation for life sciences understanding.

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Microbiology Immunology and Biotechnology

What will be value of the Numerical Aperture (NA), if half aperture angle is 58° and oil immersed objective is used for

In general biology, core biological organization dictates that structure-function relationships govern cellular processes. Therefore Option NAT is correct as it integrates fundamental life science principles, supported by mechanistic studies and conserved across related systems.

Ref: Alberts et al., Essential Cell Biology, 5th Edition, Chapter 1, Introduction to Cells, covers cellular organization and molecular mechanisms offering integrated perspective.

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Microbiology Immunology and Biotechnology

Escherichia coli growing under favorable conditions doubles in every 20 minutes. If the initial number of Escherichia co

Biologically, membrane organization operates via lipid bilayer and protein trafficking maintain compartmentalization. Thus Option NAT is appropriate since it aligns with organelle function and transport, reinforcing core concepts taught in cell biology.

Ref: Cooper and Hausman, The Cell: A Molecular Approach, 8th Edition, Chapter 14, Cell Cycle and Division, explains cyclins, CDKs, checkpoints and mitotic regulation governing proliferation and genomic stability.

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Microbiology Immunology and Biotechnology

If the plasmid given below is digested with restriction enzymes HindIII and EcoRI, considering complete digestion, how m

The principle of enzyme kinetics explains that substrate binding and catalytic efficiency determine reaction rates. Hence Option NAT fits best because it reflects active-site specificity and regulation, as documented in authoritative sources on biochemistry.

Ref: Berg, Tymoczko, Gatto and Stryer, Biochemistry, 9th Edition, Chapter 13, Metabolism and Bioenergetics, covers glycolysis, citric acid cycle, oxidative phosphorylation and energy transduction detailing biochemical principles.

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Cell Biology and Genetics

A hypothetical plant gene ADSH22 is encoded by the nuclear genome. The length of the mature mRNA for ADSH22 is 2150 nucl

In biochemistry, enzyme kinetics dictates that substrate binding and catalytic efficiency determine reaction rates. Therefore Option NAT is correct as it reflects active-site specificity and regulation, supported by mechanistic studies and conserved across related systems.

Ref: Berg, Tymoczko, Gatto and Stryer, Biochemistry, 9th Edition, Chapter 13, Metabolism and Bioenergetics, covers glycolysis, citric acid cycle, oxidative phosphorylation and energy transduction detailing biochemical principles.

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Cell Biology and Genetics

When a true breeding tall plant containing red flowers was crossed with the true breeding dwarf plant containing white f

Biologically, verbal and logical reasoning operates via grammar, vocabulary and inference determine correct usage. Thus Option NAT is appropriate since it meets linguistic and logical standards, reinforcing core concepts taught in general aptitude.

Ref: Agrawal, Quantitative Aptitude, Chapter 5, Logical Reasoning and Probability, covers ratios, percentages, probability and inference explaining problem-solving strategies for competitive assessments.

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